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Serum Immunoglobulin G (IgG) by Electrophoresis

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of Immunoglobulin G (IgG), a key protein in your immune system, using serum from a blood sample. IgG helps fight infections and is the most abundant antibody in the blood.

Quick summary

["IgG levels help assess immune function and identify potential deficiencies or excesses."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
25278-3
Short code
S pneum Da 7F IgG 2:1 Ser-Rto
Synonyms
S pneum Da 7F IgG 2:1 Ser-Rto
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What Is Immunoglobulin G (IgG)?

IgG is the primary antibody your body produces to defend against bacteria and viruses. It circulates in your bloodstream and provides long-term immunity. Low levels may indicate immune system weakness, while high levels could suggest chronic infections, autoimmune conditions, or other health concerns.

Why Might You Need This Test?

Doctors may order this test to evaluate immune function in people with frequent infections, chronic illnesses (like lupus or rheumatoid arthritis), or those receiving immune-modifying treatments. It can also help diagnose conditions like immunodeficiency or monitor antibody responses to vaccines.

Sample Collection and Preparation

A small blood sample is drawn from your arm, typically in a clinic or lab. The blood is processed to separate serum (the liquid part without clots), which is then analyzed using electrophoresis to measure IgG levels accurately.

What Does the Result Mean?

Results are compared to standard ranges, though exact values can vary by lab. Low IgG may signal immune deficiency, while very high levels could indicate chronic infections, inflammation, or certain cancers. Your doctor will interpret results in the context of your overall health and symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: When IgG Levels Matter

Short name

IgG Serum Profile

Frequently asked questions

Could my IgG levels affect my daily activities?
Low IgG levels may increase your risk of infections, but this depends on other immune factors. High levels alone often don’t cause symptoms but may require further evaluation for underlying conditions. Your doctor will guide you on lifestyle or treatment adjustments if needed.
How often should I get this test?
Frequency depends on your health condition. If you have an immune disorder, your doctor may recommend regular monitoring. Healthy individuals typically don’t need repeated testing unless symptoms arise.
What if my IgG levels are outside the normal range?
If your IgG levels are abnormal, your doctor may order additional tests (like other antibody levels or immune function tests) to find the cause. Treatment options could include immune therapy, supplements, or managing underlying conditions like chronic infections.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy